Comments

Reviewers: carrot, xur,
Message:
Hi Rong and Carrot, could you take a look at this patch, thanks!
The modification is in upstream (with a minor modification).
Background -
There is the need to agree on the runtime linker path for the various
ARM
hard-float ports that distros are working on right now. Without doing
this,
we'll break binary compatibility between the distros.
The conclusion was made. And here is the detailed information -
https://wiki.linaro.org/OfficeofCTO/HardFloat/LinkerPathCallApr2012

Patch

===== Patch starts
diff --git a/gcc/config/arm/linux-eabi.h b/gcc/config/arm/linux-eabi.hindex 3a32188..58d06c2 100644--- a/gcc/config/arm/linux-eabi.h+++ b/gcc/config/arm/linux-eabi.h@@ -32,7 +32,8 @@
while (false)
/* We default to a soft-float ABI so that binaries can run on all
- target hardware. */+ target hardware. If you override this to use the hard-float ABI
then
+ change the setting of GLIBC_DYNAMIC_LINKER_DEFAULT as well. */
#undef TARGET_DEFAULT_FLOAT_ABI
#define TARGET_DEFAULT_FLOAT_ABI ARM_FLOAT_ABI_SOFT
@@ -59,10 +60,26 @@
#undef SUBTARGET_EXTRA_LINK_SPEC
#define SUBTARGET_EXTRA_LINK_SPEC " -m " TARGET_LINKER_EMULATION
-/* Use ld-linux.so.3 so that it will be possible to run "classic"- GNU/Linux binaries on an EABI system. */+/* GNU/Linux on ARM currently supports three dynamic linkers:+ - ld-linux.so.2 - for the legacy ABI+ - ld-linux.so.3 - for the EABI-derived soft-float ABI+ - ld-linux-armhf.so.3 - for the EABI-derived hard-float ABI.+ All the dynamic linkers live in /lib.+ We default to soft-float, but this can be overridden by changing
both
+ GLIBC_DYNAMIC_LINKER_DEFAULT and TARGET_DEFAULT_FLOAT_ABI. */+
#undef GLIBC_DYNAMIC_LINKER
-#define GLIBC_DYNAMIC_LINKER RUNTIME_ROOT_PREFIX "/lib/ld-linux.so.3"+#define GLIBC_DYNAMIC_LINKER_SOFT_FLOAT \+ RUNTIME_ROOT_PREFIX "/lib/ld-linux.so.3"+#define GLIBC_DYNAMIC_LINKER_HARD_FLOAT \+ RUNTIME_ROOT_PREFIX "/lib/ld-linux-armhf.so.3"+#define GLIBC_DYNAMIC_LINKER_DEFAULT \+ RUNTIME_ROOT_PREFIX GLIBC_DYNAMIC_LINKER_SOFT_FLOAT++#define GLIBC_DYNAMIC_LINKER \+ "%{mfloat-abi=hard:" GLIBC_DYNAMIC_LINKER_HARD_FLOAT "} \+ %{mfloat-abi=soft*:" GLIBC_DYNAMIC_LINKER_SOFT_FLOAT "} \+ %{!mfloat-abi=*:" GLIBC_DYNAMIC_LINKER_DEFAULT "}"
/* At this point, bpabi.h will have clobbered LINK_SPEC. We want to
use the GNU/Linux version, not the generic BPABI version. */
Description:
Hi Rong and Carrot, could you take a look at this patch, thanks!
The modification is in upstream (with a minor modification).
Background -
There is the need to agree on the runtime linker path for the various
ARM hard-float ports that distros are working on right now. Without
doing this, we'll break binary compatibility between the distros.
The conclusion was made. And here is the detailed information -
https://wiki.linaro.org/OfficeofCTO/HardFloat/LinkerPathCallApr2012
===== Patch starts
diff --git a/gcc/config/arm/linux-eabi.h b/gcc/config/arm/linux-eabi.hindex 3a32188..58d06c2 100644--- a/gcc/config/arm/linux-eabi.h+++ b/gcc/config/arm/linux-eabi.h@@ -32,7 +32,8 @@
while (false)
/* We default to a soft-float ABI so that binaries can run on all
- target hardware. */+ target hardware. If you override this to use the hard-float ABI
then
+ change the setting of GLIBC_DYNAMIC_LINKER_DEFAULT as well. */
#undef TARGET_DEFAULT_FLOAT_ABI
#define TARGET_DEFAULT_FLOAT_ABI ARM_FLOAT_ABI_SOFT
@@ -59,10 +60,26 @@
#undef SUBTARGET_EXTRA_LINK_SPEC
#define SUBTARGET_EXTRA_LINK_SPEC " -m " TARGET_LINKER_EMULATION
-/* Use ld-linux.so.3 so that it will be possible to run "classic"- GNU/Linux binaries on an EABI system. */+/* GNU/Linux on ARM currently supports three dynamic linkers:+ - ld-linux.so.2 - for the legacy ABI+ - ld-linux.so.3 - for the EABI-derived soft-float ABI+ - ld-linux-armhf.so.3 - for the EABI-derived hard-float ABI.+ All the dynamic linkers live in /lib.+ We default to soft-float, but this can be overridden by changing
both
+ GLIBC_DYNAMIC_LINKER_DEFAULT and TARGET_DEFAULT_FLOAT_ABI. */+
#undef GLIBC_DYNAMIC_LINKER
-#define GLIBC_DYNAMIC_LINKER RUNTIME_ROOT_PREFIX "/lib/ld-linux.so.3"+#define GLIBC_DYNAMIC_LINKER_SOFT_FLOAT \+ RUNTIME_ROOT_PREFIX "/lib/ld-linux.so.3"+#define GLIBC_DYNAMIC_LINKER_HARD_FLOAT \+ RUNTIME_ROOT_PREFIX "/lib/ld-linux-armhf.so.3"+#define GLIBC_DYNAMIC_LINKER_DEFAULT \+ RUNTIME_ROOT_PREFIX GLIBC_DYNAMIC_LINKER_SOFT_FLOAT++#define GLIBC_DYNAMIC_LINKER \+ "%{mfloat-abi=hard:" GLIBC_DYNAMIC_LINKER_HARD_FLOAT "} \+ %{mfloat-abi=soft*:" GLIBC_DYNAMIC_LINKER_SOFT_FLOAT "} \+ %{!mfloat-abi=*:" GLIBC_DYNAMIC_LINKER_DEFAULT "}"
/* At this point, bpabi.h will have clobbered LINK_SPEC. We want to
use the GNU/Linux version, not the generic BPABI version. */
Please review this at http://codereview.appspot.com/6206055/
Affected files:
M gcc/config/arm/linux-eabi.h
Index: gcc/config/arm/linux-eabi.hdiff --git a/gcc/config/arm/linux-eabi.h b/gcc/config/arm/linux-eabi.hindex 3a32188..58d06c2 100644--- a/gcc/config/arm/linux-eabi.h+++ b/gcc/config/arm/linux-eabi.h@@ -32,7 +32,8 @@
while (false)
/* We default to a soft-float ABI so that binaries can run on all
- target hardware. */+ target hardware. If you override this to use the hard-float ABI then+ change the setting of GLIBC_DYNAMIC_LINKER_DEFAULT as well. */
#undef TARGET_DEFAULT_FLOAT_ABI
#define TARGET_DEFAULT_FLOAT_ABI ARM_FLOAT_ABI_SOFT
@@ -59,10 +60,26 @@
#undef SUBTARGET_EXTRA_LINK_SPEC
#define SUBTARGET_EXTRA_LINK_SPEC " -m " TARGET_LINKER_EMULATION
-/* Use ld-linux.so.3 so that it will be possible to run "classic"- GNU/Linux binaries on an EABI system. */+/* GNU/Linux on ARM currently supports three dynamic linkers:+ - ld-linux.so.2 - for the legacy ABI+ - ld-linux.so.3 - for the EABI-derived soft-float ABI+ - ld-linux-armhf.so.3 - for the EABI-derived hard-float ABI.+ All the dynamic linkers live in /lib.+ We default to soft-float, but this can be overridden by changing both+ GLIBC_DYNAMIC_LINKER_DEFAULT and TARGET_DEFAULT_FLOAT_ABI. */+
#undef GLIBC_DYNAMIC_LINKER
-#define GLIBC_DYNAMIC_LINKER RUNTIME_ROOT_PREFIX "/lib/ld-linux.so.3"+#define GLIBC_DYNAMIC_LINKER_SOFT_FLOAT \+ RUNTIME_ROOT_PREFIX "/lib/ld-linux.so.3"+#define GLIBC_DYNAMIC_LINKER_HARD_FLOAT \+ RUNTIME_ROOT_PREFIX "/lib/ld-linux-armhf.so.3"+#define GLIBC_DYNAMIC_LINKER_DEFAULT \+ RUNTIME_ROOT_PREFIX GLIBC_DYNAMIC_LINKER_SOFT_FLOAT++#define GLIBC_DYNAMIC_LINKER \+ "%{mfloat-abi=hard:" GLIBC_DYNAMIC_LINKER_HARD_FLOAT "} \+ %{mfloat-abi=soft*:" GLIBC_DYNAMIC_LINKER_SOFT_FLOAT "} \+ %{!mfloat-abi=*:" GLIBC_DYNAMIC_LINKER_DEFAULT "}"
/* At this point, bpabi.h will have clobbered LINK_SPEC. We want to
use the GNU/Linux version, not the generic BPABI version. */